An ultrasonic endoscope, comprising an insertion unit for inserting the endoscope into an abdomen being equipped with an ultrasonic probe (i.e., an ultrasonic search unit), is capable of creating a clear image of a digestive canal wall and a deep organ, such as pancreas and gall bladder, in a good image quality without being influenced by an intra-abdomen gas, or a bone, by means of an ultrasonic beam transmitted/received from/to the ultrasonic probe.
Among those ultrasonic probes, one employing an electronic scanning system consists of tens of pieces of elements, in which each element must be connected to a transmission/reception-use coaxial cable. When connecting an electrode of each element of an electronic scanning ultrasonic probe to a signal transmission/reception-use coaxial cable, a common method is to solder a core lead of the coaxial cable to the signal electrode of each element and solder a shield wire of the coaxial cable to the ground electrode of each element. The tip of the insertion part of an endoscope is equipped with such configured ultrasonic probe.
Such ultrasonic endoscopes conventionally utilized include a convex type, a linear type and a radial type. Among them, the radial type is one transmitting/receiving (noted as “transceiving” (and “transceive” as verb form) hereinafter) an ultrasonic beam in a circumferential direction, including a mechanical radial scanning system transceiving an ultrasonic beam in a radial pattern by rotating a probe and an electronic radial scanning system transceiving an ultrasonic beam in a radial pattern by means of arraying a plurality of piezoelectric elements on a circumference of a cylinder and an electronic control (e.g., refer to a patent document 1).
FIG. 1 is a diagram showing a conventional ultrasonic endoscope apparatus. The ultrasonic endoscope apparatus 160 shown in FIG. 1 comprises a connection part 161, an operation part 162 and an insertion part 163 which comprises a tip part 164.
The connection part 161 is for example connected to a display apparatus comprising a display in which an image photographed by an ultra compact camera equipped on the tip part 164 is displayed.
The operation part 162 performs an operation of curving the insertion part 163 in the up, down, left and right directions, that of expanding or contracting a balloon as described later, and other operations by a user operation.
The tip part 164 is equipped with an electronic radial array constituted by a plurality of ultrasonic transducer being continuously lined up circularly around the insertion axis as the center, in addition to the ultra compact camera, so that a predetermined ultrasonic transducer selected from among the plurality thereof transceives an ultrasonic wave. An ultrasonic wave received by the electronic radial array is also converted into an electric signal and displayed in the display, et cetera, as an image.
Incidentally, the radial array equipped on the tip part 164 includes a mechanical radial array in which a plurality of ultrasonic transducers is mechanically scanned, in addition to the electronic radial array (e.g., refer to a non-patent document 1).
FIG. 2 is an enlarged diagram of the dotted line circle A indicated in FIG. 1. As shown in FIG. 2, the tip part 164 comprises a camera part 170 equipped with the ultra compact camera, illumination, et cetera, and an ultrasonic part 171 equipped with the electronic radial array, et cetera.
FIG. 3 is a diagram exemplifying an electronic radial array. The radial array shown in FIG. 3 shows a state before individual ultrasonic transducers are formed into a circular form. The electronic radial array 180 comprises a piezoelectric element 181, an electrode 182, a first acoustic matching layer 183, a second acoustic matching layer 184, a conductive resin 185, a conductor body 186 and a substrate 187.
The piezoelectric element 181, electrode 182, first acoustic matching layer 183, second acoustic matching layer 184, conductive resin 185, conductor body 186 and substrate 187 are divided into a plurality thereof by commonly equipped grooves, resulting in comprising the plurality of ultrasonic transducers.
Then, the electronic radial array 180 is formed into a tubular form by the end surfaces in the direction perpendicular to the longitudinal direction of the electronic radial array 180 being connected to one another from the state shown in FIG. 3. Then, a lock member for locking an end of a later described balloon is mounted onto the opening part of the tubular-formed electronic radial array 180 on the side of the conductive resin 185.
Note that an ultrasonic endoscope shown in the non-patent document 1 is configured to equip the tip of a cap, which covers a mechanical radial array, with a groove to which an end of a balloon is locked.
FIG. 4 is a diagram exemplifying a lock member mounted onto an electronic radial array 11. As shown in FIG. 4, the lock member 190 is equipped with a lock groove 191 for fixing an end of a balloon.
FIG. 5 exemplifies a balloon. The balloon 200 shown in FIG. 5 is configured to be made of an elastic body such as an elastomer and formed to be tubular, and is mounted onto an ultrasonic part 171 so as to cover the electronic radial array 180.
FIG. 6 is a diagram showing how the balloon 200 is mounted onto the ultrasonic part 171. As shown in FIG. 6, one end of the opening of the balloon 200 is outserted onto a lock groove 210 featured between the camera part 170 and ultrasonic part 171, while the other end of the opening is outserted onto a lock groove 191, thereby the balloon being fixed so as to cover the electronic radial array 180.
Then, when internally filling the balloon with an ultrasonic medium 211 such as water in the state of the balloon 200 being mounted onto the ultrasonic part 171, the circumference of the electronic radial array 180 can be filled with the ultrasonic medium 211.
Thus filling of the balloon 200 with the ultrasonic medium 211 makes it possible to fill the circumference of the electronic radial array 180 with the ultrasonic medium 211, enabling an easy performance of an ultrasonic diagnosis or treatment at a spot where it is difficult to let an ultrasonic medium 211 stay, such as esophagus. It is also possible to perform an ultrasonic diagnosis or treatment in a narrow place within an abdomen because a predetermined space can be created between the electronic radial array 180 and human body by expanding the balloon 200.
In the case of constituting the ultrasonic part 171 by mounting the lock member 190 onto the electronic radial array 180 as described above, however, there is a risk of the lock member 190 falling out of the electronic radial array 180 if the connection part between the electronic radial array 180 and lock member 190 is damaged due to an unexpected physical, mechanical and/or electrical influence even though the electronic radial array 180 is attached to the lock member 190 by a strong adhesive.
FIG. 7 is a diagram showing a conventional ultrasonic endoscope apparatus. The ultrasonic endoscope apparatus 350 shown in FIG. 7 is an electronic scanning type ultrasonic endoscope apparatus, comprising a connection part 351, an operation part 352 and an insertion part 353 which comprises a tip part 354.
The connection part 351 is connected to a measurement apparatus comprising a display, for example, displaying an image obtained by an ultra compact camera equipped on the tip part 354.
The operation part 352 performs an operation of curving the insertion part 353 in up, down, left and right directions, for example, by a user operation.
The tip part 354 is equipped with an ultrasonic transducer array constituted by a plurality of ultrasonic transducer being continuously lined up, in addition to the ultra compact camera, so that a predetermined ultrasonic transducer selected from among the plurality thereof transceives an ultrasonic wave. An ultrasonic wave received by the ultrasonic transducer array is also converted into an electric signal and displayed in the display, et cetera, as an image.
FIG. 8 is an enlargement diagram of the tip part 354 shown in FIG. 7. As shown in FIG. 8, the tip part 354 comprises a scope part 355 having a photographing function such as ultra compact camera, illumination, et cetera, and the ultrasonic transducer array 356.
The ultrasonic transducer array 356 comprises an acoustic lens 357 equipped on the outside of a plurality of ultrasonic transducer, a balloon lock member 358, being equipped on one end of the acoustic lens 357, for locking an end of a later described balloon, and a scope connection member 359 equipped between the end of the acoustic lens 357 and the scope part 355.
As described above, the ultrasonic endoscope apparatus 350 is commonly used by mounting a balloon made of an elastomer onto the ultrasonic transducer array 356 (e.g., refer to a patent document 2).
FIG. 9 is a cross-sectional diagram of the ultrasonic transducer array 356 on which a balloon is mounted. In this diagram, the same component sign is assigned to the same configuration as one shown in FIG. 8. The balloon 360 shown in FIG. 9 is for example configured as a tube which is made of an elastic body as elastomer. One end of the opening of the balloon 360 is latched to a balloon lock groove 361 featured on the circumference of the scope part 355 while the other end of the opening of the balloon 360 is latched to an balloon locking groove 362 featured on the circumference of the balloon lock member 358, thereby the balloon 360 being mounted onto the ultrasonic transducer array 356 so as to cover the acoustic lens 357.
Then, when the balloon 360 is internally filled with an ultrasonic medium 363 such as water in the state of the balloon 360 being mounted onto the ultrasonic transducer array 356, the circumference of the acoustic lens 357 can be filled with the ultrasonic medium 363.
Thus filling of the balloon 360 with the ultrasonic medium 363 makes it possible to fill the circumference of the acoustic lens 357 with the ultrasonic medium 363, enabling an easy performance of an ultrasonic diagnosis or treatment at a spot where it is difficult to let an ultrasonic medium 363 stay, such as esophagus.
It is also possible to perform an ultrasonic diagnosis or treatment in a narrow place within an abdomen because a predetermined space can be created between the ultrasonic transducer array 356 and human body by expanding the balloon 363.
In the case of constituting the ultrasonic transducer array 356 by an acoustic lens 357, a balloon lock member 358 that is an endoscope structure member and a scope connection member 359, as the above noted ultrasonic endoscope apparatus 350, however, the acoustic lens 357 is generally structured by a soft material such as elastomer, while the balloon lock member 358 and scope connection member 359 are generally structured by a plastics, et cetera. As such, the acoustic lens 357 is structured by a different material than that of the balloon lock member 358 and scope connection member 359, and therefore the acoustic lens 357, balloon lock member 358 and scope connection member 359 cannot be integrally structured. Due to this, it is necessary to equip a connection band constituted by an adhesive, et cetera, between the acoustic lens 357 and balloon lock member 358, and also between the acoustic lens 357 and scope connection member 359, in order to connect the acoustic lens 357 to the balloon lock member 358, and connect the acoustic lens 357 to the scope connection member 359. If either of the both end parts of the acoustic lens 357 is featured to be protrusive than the balloon lock member 358 or scope connection member 359 in this event, such a protrusion causes the problem of the ends of the acoustic lens 357 becoming prone to receiving a force from the balloon 360, resulting in levying loads at the both ends of the acoustic lens 357, respectively, when mounting the balloon 360 onto the ultrasonic transducer array 356 or removing the balloon 360 therefrom.
And if the respective loads are levied at the both ends of the acoustic lens 357 at the time of mounting or removing the balloon 360, the caused problem includes the mounting or removal of the balloon 360 becoming difficult or the acoustic lens 357 peeling off.
And, it is necessary to consider the safety for a human body in designing an endoscope since it is an instrument to be inserted internally to a body cavity. Because the outer surfaces of the insertion part and its tip part (i.e., an ultrasonic probe) are covered with an insulative resin, the internal signal wire is not conceivably externally exposed.
If the plastics covering the outer surfaces are damaged, however, there is a possibility of the signal wire being externally exposed. In such an event, an electric shock can be avoided by the entirety of the signal wire being covered with a protective grounded metal.    Patent document 1: Japanese registered patent Sho 63-14623    Patent document 2: Japanese registered patent Hei 06-13034    Non-patent document 1: Electronic Industries Association of Japan (currently, Japan Electronics and Information Technology Industries Association): Handbook of Ultrasonic Diagnostic Equipments, pp. 114; published by Corona Publishing Co., Ltd.; Jan. 20, 1997